Cathode-ray tube sealing apparatus



June 24, 1952 J, HARDER, JR 2,601,518

CATHODE-RAY TUBE SEALING APPARATUS Filed Nov. 17, 1949 2 SHEETS-SHEET 1 Fig.1

C GOJERNOR AIR CYLINDER INVENTOR. APT/wk mean, we

HIS ATTORNE June 24, 1952 A. J. HARDER, JR 2,601,518

CATHODE-RAY TUBE SEALING APPARATUS Filed Nov. 17, 1949 2 SHEETS-SI-IEET 2 IN V EN TOR. ARTHUR u. #4 20:9, JP- m HIS ATTORNEY Patented June 24, 1952 CATHODE-RAY TUBE SEALING APPARATUS Arthur J. Harder, Jr., Chicago, Ill., assignor to The Rauland Corporation, a corporation of Illinois Application November 17, 1949, Serial No. 127,975

4 Claims.

This invention relates to apparatus for the fabrication of cathode-ray tubes of the type having an envelope comprising a tubular neck portion of vitreous material such as glass or the like, a metallic conical portion, and a transparent window or viewing plate of glass or similar transparent plastic. More particularly, this invention is directed to an improved mechanism for releasably supporting a tubular neck portion of a cathode-ray tube envelope in such apparatus.

Apparatus for sealing together the above-mentioned components of a cathode-ray tube envelope is disclosed in copending application Serial No.

122,231, filed October 19, 1949, in the name of Albert L. Buttino entitled Cathode-Ray Tube Sealing Apparatus; and in copending application Serial No. 127,457 filed November 15, 1949, in the name of Arthur J. Harder Jr., entitled Cathode-Ray Tube Sealing Apparatus; both assigned to the present assignee.

The present invention provides a releasable mechanism for firmly supporting a tubular member. such as the vitreous neck portion of a cathode-ray tube envelope, in a desired position; and the mechanism may be incorporated into the apparatus disclosed in the aforementioned applications, or similar types of apparatus.

It is accordingly, an object of this invention to provide an improved releasable mechanism for firmly supporting a tubular member, such as the tubular neck portion of a cathode-ray tube envelope, in cathode-ray tube sealing apparatus or the like.

A further object of this invention is to provide an improved supporting mechanism which is simple and convenient to operate, which firmly supports a tubular member in a desired position for sealing or other operations, and which may be quickly triggered to release the tubular member and enable it to be removed.

The features of this invention which are believed to be new are set forth with particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof may best be understood by reference to the following description when taken in conjunction with the accompanying drawings, in which:

Figure 1 shows a supporting mechanism of the present invention incorporated into a cathoderay tube sealing machine.

Figure 2 shows an enlarged view, mostly in section, of the supporting mechanism of the present invention,

Figure 3 shows a view of the supporting mechanism of Figure 2 taken along the lines 3-3, and Figure 4 shows a view of the supporting mechanism of Figure 2 taken along the lines 4-4.

Reference is now made to Figure 1 wherein the illustrated sealing apparatus is similar in many respects to those disclosed in the aforementioned copending applications. The illustrated apparatus includes a table 20 having a top 2| and a shelf 22. An electrical motor 23 is mounted on the shelf 22 to rotate a drive tube 24 by means of a belt drive 25. The belt drive 25- is coupled to a drive wheel 26 rotatably mounted on tube 24, and motion is translated from the wheel 26 to the drive tube 24 through a frictional clutch arrangement. This clutch arrangement comprises a collar 21 fixed to the tube24, a pressure spring 28 and a pressure plate 29 holding the spring against the wheel 26 with a predetermined pressure. This arrangement provides a friction drive from the wheel 26 to the pressure plate 29 and, hence, to the drive tube 24. The drive tube 24 has a spindle 30 mounted thereon so that rotation of this tube by the motor 23 causes the spindle to rotate. i

A lift tube 3| is mounted coaxially within the drive tube 24 in frictional engagement with the drive tube for rotation therewith, and extends beyond the spindle 30 into a cylindrical cam arrangement 32. prises a cylindrical housing 33, a first cylindrical cam 34 fixed to the lift tube 3| by means of a shoulder 35, and a second cylindrical cam 36 engaging the cam 34. The cam 36-is rotatable to give it a variable displacement from the cam 34, for reasons to be described, and may be locked at any selected displacement therefrom by means of a locking rod 31 threaded through cam 36 against the surface of lift tube 3|.

A lift arm 38 is mounted under shelf 22 on a pivot 39. One extremity of the lift arm is coupled to a pin 40 carried by the lift tube 3|, and the other end of the lift arm 38 is coupled to the plunger 4| of an air cylinder 42, and to the plunger 43 of a hydraulic governor 44. The governor 44 has the function of reducing the speed of travel of the plunger 4| of air cylinder 42, and it operates in well known manner to provide constant low speed to its plunger '43 regardless of the pressure exerted on this plunger by theair cylinder plunger 4| through the arm 38. The downward travel of the plunger 4| and, thus, the upward movement of the lift tube 3|, is limited by a bracket 45 and adjusting screw 46.

An air tube 41 is mounted coaxially within the lift tube 3| in frictional engagement with the The cam arrangement 32 com lift tube for rotation therewith. A rotary air seal 48 of well known construction is mounted on the lower extremity of the air tube, and air is introduced into the air tube from a source, not shown, through a rubber tube 49. The air tube 41 extends beyond the cam arrangement 32 and through a mechanism 56 (to be described in detail hereinafter) which supports the tubular neck H of a cathode-ray tube envelope. The tube 41 is fixed to the cylindrical cam 36 by means of a shoulder so that adjustment of the position of cam 36 relative to cam 34 varies the relative displacement of the air tube 41 within the lift tube 3|.

A pair of spindle rods 69 are mounted on the spindle 30 and extend upwardly to support an annular bracket 6| at their uppermost extremities. The bracket 6|, in turn, serves as a support for the metal cone l6 of a cathode-ray tube envelope. A plurality of gas burners l4 are mounted on a ring 63 surrounding the assembly ill-H, and this ring is supported by collars 64 adjustably mounted on vertically extending guide rods 65. The position of the ring 63 and, hence, of the burners |4 may be adjusted by loosening set screws 66 and moving collars 64 along the guide rods 65.

The operation of the apparatus is as follows: The gas'burners M are turned off or to a low pilot level. The tubular neck II is placed on the supporting mechanism 56 and, in a manner to be described, is firmly held thereon coaxially with the air tube 41 and with its lower end sealed from the atmosphere. The metal cone I0 is placed in the annular bracket 6| and tapped into place so that its axis is in a vertical position and coaxial with the air tube 41. A glass window |2 may be placed in a flange l3 which circumscribes the large upper end of the cone Ill.

The rod 31 is loosened and the cam 36 is rotated until the air tube 41 has a longitudinal displacement within the lift tube 3| to provide a distance :r (for example between the upper rim of the flared section Ha and the lower rim of cone Ill. The distance .2? may be established by a feeler gauge or other suitable tool inserted between the neck and the cone. Once the distance a: is set up the rod 31 is tightened. The neck H and cone H) are rotated in unison by means of the motor 23. A soft flame may be played over the flared portion Ila of the neck II and when this portion is sufiiciently heated thereby, the gas burners M are ignited and directed onto the lower portion of the cone M to heat locally this portion. At the same time a soft, bushy, flame may be played over the top surface of the window I2 to ensure uniform heating of the window.

When the glass rim of the section I la reaches a plastic state due to heat radiated from the heated lower portion of the cone, air is introduced into the air cylinder 42 causing the lift arm 38 to move against the action of the hydraulic governor 44, in turn causing the lift tube 3| to rise slowly, thereby moving the flared portion Ila of neck into contact with the lower rim of cone Ill. The downward travel of the plunger 4| of air cylinder 42 and, thus, the upward travel of the neck II, is arrested by the screw 46 which is adjustable to establish a desired amount of contact between the flared portion Ha and the lower rim of cone It.

The burners M are turned on" before the rim of section Ila becomes excessively molten and runs," so that a satisfactory seal is produced between the neck and the cone. The flange |3 of the cone |0 may now be locally heated by any suitable heating elements to seal the window i2 to the cone. Air is introduced through the rubber tube 49 and rotary air seal 48 into the air tube 4'! and, hence, into the interior of the cone Ill to prevent the edge of window l2 from sagging during the window sealing operations. After the edge of the Window I2 has reached a plastic state, the heating elements locally heating the flange l3 are turned off, and the edge settles into the flange sealing the window to the cone.

The present invention is directed to the supporting mechanism or neck chuck 50, and may best be understood by reference to Figure 2. As illustrated in Figure 2, the mechanism 59 comprises an annular wedge 19 coaxial with and secured to the air tube 41 by means of a set screw H, or threaded to the air tube if so desired. A second annular wedge 12 is slidably mounted on and coaxial with air tube 41 below wedge 16. A third annular wedge 13 is slidably mounted on the air tube below the wedge 12. The wedges l9 and 12 are separated by an annular wedge, comprising a plurality of arcuate segments 14 which are urged inwardly by means of a circumscribing spring 15 lying in slots 16 formed in these segments. The wedges l2 and i3 are separated by a further wedge comprising a plurality of arcuate segments ll urged upwardly by means of a circumscribing spring 18 lying in slots 19 cut in these segments. A rubber air seal is mounted coaxially with the air tube 41 directly below the wedge 13 and separates this wedge from a collar 8| slidably mounted on the air tube. A pair of support rods 82 for the neck portion I extend radially from the air tube 4! through longitudinal slots 83 in the collar 8|.

When no upward pressure is exerted on the collar 8|, and it is in a first position, the seg' ments 14 and 11 are forced inwardly toward the axis of air tube 41 by the circumscribing springs l5, l8; and the wedges 12, 18, air seal 80 and collar 8| are forced downwardly due to the action of the segments 14 against the fixed wedge 10. When the supporting mechanism 56 is in this condition the neck may be placed over the chuck mechanism to rest on the rods 82. When the collar 8| is forced upwardly relative to the air tube 41 to a second position the segments 14 and 11 are forced outwardly against the inside surface of the neck due to the upward movement of the wedges 12, 13 relative to the fixed wedge 16, and the air seal 89 is forced upwardly into the neck I sealing the lower end of the neck. When the mechanism 59 is in this latter condition the neck I is firmly supported thereby and air sealed at its lower end by the seal 89.

A cylindrical member 84 is slidably mounted on the air tube 41 and this member has a pistonlike center portion 85. A further cylinder 86 is supported in fixed relation with the air tube 41 on the cylindrical cam 36, and is mounted coaxially with the piston so that the piston may move reciprocally therein. This piston 85 is surrounded by the coil spring 8'! so that the member 34 is urged upwardly relative to the air tube 41 and away from the cylinder 86.

A control arm 88 is pivoted to a bracket 89 fixed to the cylinder 85, and is mechanically coupled to the member 84 by means of a pin 90. When downward pressure is exerted on the arm 88, the piston 85 is forced into the cylinder 86 against the action of the spring 81'. A latch 9| is pivoted to an arm 92-fixed to the cylinder 86 and urged in a counterclockwise direction by a spring 93. When the arm 88 is forced downward to an extreme position, the latch 9| engages a rod 94 and holds the arm in this position. To return the arm to its extreme upward position, it is merely necessary to release the latch 9| by rotating it in a clockwise direction about its pivot.

Therefore, to place the neck over the supporting mechanism 50, the arm 88 is moved downward to its latched position. This removes the pressure from the collar 8| and, as previously described, causes the springs 15, 18 to move segments 14, ll inwardly and the air seal 80 to move downwardly. The neck I I may now be placed on the rods 82 and the latch 9| released. The release of latch 9| causes the coil spring 81 to force the member 84 upwardly against the collar 8| which, in turn, causes the segments 74, l! to spread outwardly to the inside surface of the neck I and air seal 89 to move upwardly into the neck. In this manner, the neck is firmly supported by the mechanism 50 coaxially with the tube 41, and the lower end thereof is air sealed by the seal 80. To release the neck for removal from the chuck mechanism, the arm 88 is merely again moved downward to its latched position.

Figure 3 shows a section of the supporting mechanism 5|] taken along the lines 3-3 of Figure 2 and represents clearly the configuration of the segments 11 of the annular wedge.

Figure 4 shows a section of the supporting mechanism 50 taken along the lines 44 of Figure 2 and indicates clearly the shape and arrangement of the control arm 88 and latch 9 I.

This invention provides, therefore, an improved supporting mechanism for cathode-ray tube sealing apparatus or the like, which holds a tubular neck portion of the cathode-ray tube envelope in a desired position for sealing or other operations, and which may be quickly and easily triggered to release the neck when these operations are completed.

While a preferred embodiment of the invention has been shown and described modifications may be made therein, and it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

I claim:

1. A chuck mechanism for releasably holding a tubular member comprising: a shaft; a first annular wedge secured to said shaft and having a cam surface at one end sloping in one sense; a second annular wedge slidably supported on said shaft and having a cam surface facing said cam surface of said first wedge but sloping in the opposite sense; a third annular wedge, coaxial with but positioned intermediate said first and second wedges, comprising a plurality of arcuate segments presenting a complementary cam surface to said cam surfaces of said first and second wedges and a circumscribing resilient member urging said segments toward the axis of said shaft; a collar slidably mounted on said shaft adjacent said second wedge and movable between a loading position in which said resilient member drives said segments towards the axis of said shaft to permit a tubular member to be placed over said wedges and a locking position in which said collar drives said second wedge toward said first wedge to force said segments away from said shaft into firm engagement with the inner surface of said tubular member; a spring member for driving said collar to said locking position; a control arm for displacing said collar from said 6 locking position to said loading position; and a latch for engaging said control arm to secure said collar in said loading position. i

2. A chuck mechanism for releasably holding a tubular member comprising: a vertically extending shaft; a first annular wedge secured to said shaft and having a cam surface at its lower end sloping in one sense; a second annular wedge slidably supported on said shaft below said first wedge and having a cam surface facing said cam surface of said first wedge but sloping in the opposite sense; a third annular wedge, coaxial with but positioned intermediate said first and second wedges, comprising a plurality of arcuate segments presenting a complementary cam surface to said cam surface of said first and second wedges and a circumscribing resilient member urging said segments towards the axis of said shaft; a flexible air seal slidably mounted on said shaft below said second wedge; a collar slidably mounted on said shaft below said air seal and movable between a loading position in which said resilient member drives said segments towards the axis of said shaft to permit a tubular member to be placed over said wedges and a locking position in which said collar drives said second wedge toward said first wedge to force said segments away from said shaft into firm engagement with the inner surface of said tubular member and further driving said air seal into said tubular member; a spring member for driving said collar to said locking position; a control arm for displacing said collar from said locking position to said loading position; and a latch for engaging said control arm to secure said collar in said loading position.

3. A chuck mechanism for releasably holding a tubular member comprising: a vertically extending shaft; a first annular wedge secured to said shaft and having a cam surface at its lower end sloping in one sense; a second annular wedge slidably supported on said shaft below said first wedge and having a cam surface facing said cam surface of said first wedge but sloping in the opposite sense; a third annular wedge, coaxial with but positioned intermediate said first and second wedges, comprising a plurality of arcuate segments presenting a complementary cam surface to said cam surface of said first and second wedges and a circumscribing resilient member urging said segments towards the axis of said shaft; a collar slidably mounted on said shaft below said second wedge and having at least one longitudinal slot formed therein; at least one radially extending rod fixed to said shaft and protruding through said slot for supporting a tubular member coaxial with said shaft surrounding said wedges; a cylindrical member slidably mounted on said shaft below said collar and movable between a loading position in which said resilient member drives said segments towards the axis of said shaft to permit said tubular member to be placed over said wedges on said supporting rod and a locking position in which said cylindrical member drives said second wedge towards said first wedge to force said segments away from said shaft into firm engagement with the inner surface of said tubular member; a spring member for driving said cylindrical member to said locking position; a control arm for displacing said cylindrical member from said locking position to said loading position; and a latch for engaging said control arm to secure said cylindrical member in said loading position.

4. A chuck mechanism for releasably holding a tubular member comprising: a vertically extending shaft; a first annular wedge secured to said shaft; a pair of annular wedges mounted below said first wedge coaxiall-y therewith each comprising a plurality of arcuate segments and a circumscribing resilient member for urging said segments toward the axis of said shaft; a fourth annular wedge slidably mounted on said shaft intermediate said pair of annular wedges; a fifth annular wedge slida'bly mounted on said shaft below the lower one of said pair of annular wedges; a collar slidably mounted on said shaft below said fourth wedge and having a pair of longitudinal slots formed therein; a pair of radially extending rods fixed to said shaft and protruding through said slots for supporting said tubular member coaxially with said shaft surrounding said wedges; a cylindrical member slidably mounted on said shaft below said collar and movable between a leading position in which said resilient members drive said segments toward the axis of said shaft to permit said tubular member to be placed over said wedges on said supporting rods and a locking position in which said cylindrical member drives said fifth wedge towards said first wedge to force said segments away from said shaft into firm engagement with the inner surface of said tubular member; a spring memher for driving said cylindrical member to said locking position; a control arm for displacing said cylindrical member from said locking position to said loading position; and a latch for engaging said control arm to secure said cam in said loading position.

ARTHUR J. HARDER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,182,008 Goldstone May 9, 1916 2,348,819 Johnson May 16, 1944 FOREIGN PATENTS Number Country Date 316,102 Italy Mar. 20, 1934 

